Apparatus useful in ultrasonic inspection of pipes



Sept. 13, 1966 L. O. STEBBINS APPARATUS USEFUL IN ULTRASONIC INSPECTION OF PIPES Filed May 9, 1963 2 Sheets-Sheet 1 0 INVENTOR. 4429/ a 575554446 Q Q g Q A 770/Q/VEK5 p 1966 L. o. STEBBINS 3,272,000

APPARATUS USEFUL IN ULTRASONIC INSIECTION OF PIPES Filed May 9, 1963 2 Sheets-Sheet 2 INVENTOR. Z/JEPV a 57Z55/A/6 BY 6M6 United States Patent 3,272,000 APPARATUS USEFUL IN ULTRASONIC INSPECTION OF PIPES Larry 0. Stebbins, Boulder, Colo., assignor to Automation Industries, Inc., El Segundo, Calif., a corporation of California Filed May 9, 1963, Ser. No. 279,147 8 Claims. (Cl. 73-715) The present invention relates to apparatus useful in ultrasonic inspection of pipes, tubing, drill strings used in oil field installations and the like.

Briefly, the apparatus described herein involves an ultr-asonic transducer mounted on a wheeled carriage which is adapted to be moved through a pipe, tubing or casing with spring-urged wheels and a spring-urged transducer head contacting the inner surface of such pipe for ultrasonic inspection of the same. The carriage has an electrical connector for the transducer and also a water passage therein for the introduction of water that couples the transducer to the pipe, tubing or casing being inspected.

It is therefore a general object of the present invention to provide new and useful apparatus constructed and functioning in the manner indicated above.

A specific object of the present invention is to provide apparatus of this character useful in pipes of different diameters.

Another specific object of the present invention is to provide apparatus of this character which assures good electrical coupling between the transducer and the pipe in those instances where the internal surface of the pipe has irregularities.

Another specific object of the invention is to provide apparatus of this character wherein the wheels are mounted to assure substantially straight-line tracking when and as the apparatus is moved through pipe.

Another specific object of the invention is to provide apparatus of this character using a novel transducer mounting.

Another specific object of the invention is to provide apparatus of this character which may be subjected to rough handling without damage to the transducer.

The featuures of the present invention which are believed to be novel are set forth with particularity in the appended claims. This invention itself, both as to its organization and manner of operation, together with further objects and advantages thereof, may be best understood by reference to the following description taken in connection with the accompanying drawings in which:

FIGURE 1 is a view in side elevation of apparatus embodying features of the present invention.

FIGURE 2 is a vie-w taken generally along the line 22 of FIGURE 1.

FIGURE 3 is a sectional view taken along the line 3-3 of FIGURE 2.

FIGURE 4 is a perspective view showing the transducer used in FIGURE 1 on its mounting base.

FIGURE 5 is a view taken in the direction indicated by the arrows 55 in FIGURE 2.

FIGURE 6 is a perspective view showing a mounting block used in the construction of FIGURE 1.

FIGURE 7 is a sectional view taken along the line 77 of FIGURE 10.

FIGURE 8 is a view taken along the line 88 in FIGURE 7.

FIGURE 9 is a sectional view taken along the line 99 in FIGURE 7.

FIGURE 10 is a view taken along the line 10-10 in either FIGURE 7 or FIGURE 1.

FIGURE 11 is a view taken along the line 11-11 in FIGURE 3.

The apparatus shown in the drawings is essentially a cylindrical carriage 10 formed .from cylindrical metal stock and has three spring-urged wheels 11 at each end thereof, forming a part of the caster 12 which is springurged outward-1y. A typical mounting for each of the casters is illustrated in FIGURE 3 wherein the caster 12 has a shaft 14 of a spring-urged tubular spring follower or seat 16 secured thereto. This spring follower 16 is slidably received within a blind bore in a circular cross-sectioned support 18, the support 18 being secured within a bore 19 of the carriage member 10 by set screws 22 as shown also in FIGURE 11. The spring follower 16 has a pin 23 extending radially therethrough, with the ends of the pin 23 slidably cooperating with slotted portions 18A and 18b in support 18 for guiding movement of the spring follower 16. A ball-bearing thrust bearing 24 is positioned between a shouldered portion of the fol-lower 16 and caster 12 and is retained by a snap ring 26 on the end of shaft 14.

It will be seen from the drawings that the supporting shaft 14 for each of the casters is inclined with respect to the longitudinal axis of carriage 10, the shaft axes each extending through the center of the axis of the cylindrical carriage member 10 and with each shaft axis offset in the direction of the adjacent end of the carriage to make an acute angle with the axis of the carriage.

It is noted also that the caster shaft 30 for each caster wheel 11 is offset in the direction of the corresponding end of carriage member 10, ie the axis of shaft 14 does not pass through the axis of shaft 30 which is dispaced from the shaft axis 14 toward the adjacent end of the carriage 10. This construction facilitates assembly of the apparatus within .a pipe as well as good tracking of the carriage when and as it is being pulled or moved through the pipe.

The carriage 10 may be pulled through the pipe using a rope or wire cable attached to clevises 32 and 33 on opposite ends of the carriage 10, such clevises 32 and 33 each having a corresponding threaded shank 34 and 35 threaded into corresponding walls of carriage 10 as typi- -fied in FIGURE 3. These shanks 34 and 35 may be threaded into tapped holes 50 having their axes coincident with the axis of carriage member 10 or, alternatively, such shanks 34 and 35 may be threaded into bore holes 39 which have their axes offset with respect to the longitudinal axis of the cylindrical carriage member 10, as shown in FIGURE 3. When the shanks 34 and 35 are secured in their corresponding tapped holes 40, the carriage 10 is moved without turning about its axis; and when such shanks 34 and 35 are threaded in their corresponding offset taped holes 39, the carriage 10, during its longitudinal movement, rotates also about its axis for spirally scanning the interior surface of the pipe. If desired, the clevises 32 and 33 may be swivelly mounted on their corresponding shanks 3'4 and 35. To assure such spiral movement of the carriage 10, the caster supports 18 are adjustably positioned, using set screws 22, such that different wheel shafts 30, in each set of three wheels, are progressively spaced in the direction of adjacent ends such that a plane passing through the axes of the three shafts of a set makes an acute angle with respect to the longitudinal axis of the cylindrical carriage 10.

The cylindrical carriage 10 is centrally apertured and formed to receive the transducer 50 (FIGURE 4) of conventional construction comprising a crystal suitably mounted in a housing. The transducer unit 50 is mounted on a base member 51 and assembled on the carriage 10 in the manner now described in connection with FIGURES 710. A screw 52 secures the crystal unit 50 to its base member 51 which, in turn, is resiliently mounted on a mounting block 53 (FIGURE 6) using four mounting bolts 55, each of which passes through a corresponding coil compression spring '56 and is threaded in the mounting block 53, each of such springs '56 being compressed between the base plate 51 and mounting block 56, and the mounting block 53, in turn, being resiliently supported using the following construction.

The mounting block 53 has secured thereto a pipe wall engaging member 60 using two bolts 62 which are threaded into the support block 53 and which, as shown in FIGURE 10, serve also to retain a pair of bent rods 64 in outer grooved portions of the member 60, such rods 64 serving as skids and being also retained in such grooved portions by pins 66.

The mounting block 53, thus secured to the pipe-engaging member 60, is resiliently mounted on a pair of support members 70 and 71 (FIGURES 7 and 8) which are retained in internal slot-ted portions of the carriage by bolts 72. For this purpose each of a pair of bolts 80 and 81 pass through a corresponding coil compression spring 82, 83 and is threaded in a corresponding one of the blocks 70, 7-1, the coil compression springs 82 and '83 being compressed between the member 60, on the one hand, and correspondingly between the support blocks 70 and 71.

Thus, using this construction, the pipe wall engaging member 60 and support block 53, mounted as a unit, are resiliently mounted on the carriage 10, and, in turn, the transducer 50 is resiliently mounted on the mounting block 53. In other words, the crystal or transducer unit 50 is shock-mounted on the support member 53 which, in turn, is resiliently mounted on the carriage 10. The wall contact member 60 is guided in its movement by a rectangular apertured guide member 90 which is secured to the carriage member 10 by bolts 92 (FIGURE 9).

One side of the centrally apertured carriage 10 has a water-tight cover member 94 of transparent material secured by fastening bolts 96.

Water is introduced into the interior of the carriage 10 through a suitable fitting 100 (FIGURE 1) which is in communication with the channel 107 (FIGURES 3, 9 and 7) leading to that space within which the crystal '50 is mounted. The crystal 50 is electrically connected to an electrical coaxial fitting 104 (FIGURE 2) through a coaxial cable 105 (FIGURES 9 and 8), the cable 105 extending through a channel 107 in member 10.

The member 60 has its outer face contoured generally to fit against the inner circular wall of the pipe under investigation, but water leakage may occur between member 60 and the pipe since it is contemplated that water under pressure is supplied to the fitting 100 so that at all times there is a solid Water column between the transducer '50 and the inner wall of the pipe whereby a good ultrasonic coupling exists at all times between the transducer 50 and such interior wall of the pipe which is encompassed by the generally rectangular apertured portion 60A (FIGURE 10) of the contoured member 60.

It is thus contemplated that when and as the carriage 10 is either positioned or moved within a pipe under investigation, the transducer 50 is electrically connected to conventional electronic equipment for analyzing energy periodically reflected from the pipe with such energy being transferred through a solid water column between the pipe and transducer 50 with the transducer 50 serving not only as a transmitting crystal but also as an echo receiving crystal.

During such movement of the apparatus, the apparatus conforms to the particular internal dimensions of the pipe and in such case there is a permissive movement of the head 60 to allow it to conform generally with such changing dimensions. The springs 82 and 83, which urge the head 60 against the inner wall of the pipe at all times, are stronger than the springs 56 that serve to shockmount the transducer unit 50.

While the particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

I claim:

1. Apparatus for the inspection of metal pipe wherein a transducer is mounted to transmit energy pulses into the pipe and to receive resulting echo signals therefrom, the combination comprising, a generally cylindrical body which is radially apertured at a central portion thereof to provide a central apertured portion, three casters on each end of said body, means slidably mounting each of said three casters near each end of said body, each of said casters having a pipe-engaging wheel rotatable about its wheel axis, each of said casters having a supporting shaft which is slidably mounted on said body and about the axis of which said wheel may be oriented, individual spring means acting between said body and a corresponding one of said shafts and urging said wheels outwardly, the axis of each shaft and the corresponding wheel axis being at right angles and being displaced in nonintersecting relationship, the axis of each shaft making an acute angle with the longitudinal axis of said body, means mounted on opposite ends of said body for exerting a pulling force on said body whereby said body may be pulled through a pipe with said spring-urged wheels engaging and rotating on the inner surface of said pipe, a transducer, an apertured pipe-engaging member providing an open window for said transducer, first resilient means, means incorporating said first resilient means and resiliently mounting said pipe-engaging member on said body, second resilient means, means incorporating said second resilient means and resiliently mounting said transducer means on said pipe-engaging member, said first resilient means being stronger and exerting a greater force than said second resilient means, water conduit means in communication with said central apertured portion for conducting water to said transducer and through said open window to an interior surface of the pipe.

2. Apparatus of the character described for the inspection of metal pipe wherein a transducer is mounted to transmit energy pulses into the pipe and to receive echo signals therefrom, the combination comprising, an elongate body which is apertured at a region intermediate its ends to provide an apertured portion, pipe-engaging wheels mounted on said body, individual spring means acting between said body and each wheel urging the same into contact with the interior wall of the pipe, a transducer within said apertured portion, a pipe-engaging member, means resiliently mounting said member on said body, means mounting said transducer on said member, said member being shaped to provide a window for the transducer, and Water conduit means in said body communicating With said apertured portion for the flow of water to said apertured portion, to said transducer and through said window.

3. Apparatus for the inspection of metal pipe wherein a transducer is mounted to transmit energy pulses into the pipe and to receive resulting echo signals therefrom, the combination comprising, an elongate body which is apertured at a region intermediate its ends to provide an apertured portion, wheels on said body, each of said wheels having an axle and an axle support, individual means resiliently supporting each of said axle supports on said body, a transducer in said apertured portion, a pipe engaging member, means resiliently mounting said member on said body for resiliently pressing said member against the interior wall of said pipe, said member being perforate to provide a window for the transducer, and means mounting said transducer on said member, and water conduit means in said body for conveying water to said apertured portion, to said transducer and through said window.

4. Apparatus as set forth in claim 3 in which said wheels are each part of a caster in which the wheel may turn on said axle support for orientation of the wheel.

5. Apparatus as set forth in claim 4 in which the axes of a wheel axle and the corresponding axle support are at right angles to each other and are displaced from each other in nonintersecting relationship.

6. Apparatus as set forth in claim 3 in which the means mounting said transducer on said member is resilient to allow movement between said transducer and said member.

7. Apparatus as set forth in claim 3 in which said apertured portion extends transversely through said body and is closed at one of its ends by a removable sealing plate.

8. Apparatus of the character described for the inspection of pipe wherein a transducer is mounted to trans-- mit energy pulses into the pipe and to receive echo signals therefrom, the combination of, an elongated body for traveling through said pipe, said body including mounting means to provide a support portion, means mounted on said body for being maintained in moving contact with the interior wall of the pipe when said body is inside said pipe, a transducer disposed in said support portion, a

References Cited by the Examiner UNITED STATES PATENTS 2,519,221 8/1950 Bogen et al 33178 2,678,559 5/1954 Drake 73-678 3,190,112 6/1965 Beaujard et al 73-67.8 X 3,209,582 10/1965 Greenberg et a1 73-67.8

FOREIGN PATENTS 540,371 4/1957 Canada.

RICHARD C. QUEISSER, Primary Examiner. JOHN P. BEAUCHAMP, Assistant Examiner. 

8. APPARATUS OF THE CHARACTER DESCRIBED FOR THE INSPECTION OF PIPE WHEREIN A TRANSDUCER IS MOUNTED TO TRANSMIT ENERGY PULSES INTO THE PIPE AND TO RECEIVE ECHO SIGNALS THEREFROM, THE COMBINATION OF, AN ELONGATED BODY FOR TRAVELING THROUGH SAID PIPE, SAID BODY INCLUDING MOUNTING MEANS TO PROVIDE A SUPPORT PORTION, MEANS MOUNTED ON SAID BODY FOR BEING MAINTAINED IN MOVING CONTACT WITH THE INTERIOR WALL OF THE PIPE WHEN SAID BODY IS INSIDE SAID PIPE, A TRASDUCER DISPOSED IN SAID SUPPORT PORTION, A PIPE-ENGAGING MEMBER, MEANS RESILIENTLY MOUNTING SAID MEMBER ON SAID BODY ADJACENT SAID INTERIOR WALL OF SAID PIPE, SAID MEMBER BEING SHAPED TO PROVIDE A WINDOW FOR THE TRANSDUCER, MEANS MOUNTING SAID TRANSDUCER ON SAID MEMBER FOR COUPLING SAID TRANSDUCER TO SAID WINDOW, AND, WATER CONDUIT MEANS IN SAID BODY COMMUNICATING WITH SAID WINDOW FOR THE FLOW OF WATER THROUGH SAID WINDOW TO COUPLE SAID TRANSDUCER TO SAID INTERIOR WALL. 